Tree climbing is as old as mankind, but recently, elevation junkies have started signing on to learn the proper way to hit the upper leaves. At Atlanta-based Tree Climbers International (404/377-3150;; $12 for a three-hour beginners' clinic), enrollment has doubled in the past two years, says instructor Peter "Treeman" Jenkins. Below, Jenkins describes the best way to branch out.

What do you love best about your profession?
I often spend the night in a lofty hammock, calling to owls. They fly over to see if I'm eating their mice. I like communicating with animals.

What's your favorite type of tree to climb?
An 80-foot-tall, 18-inch-diameter pine, which whips vigorously in the breeze. I call riding the wind up there branch-surfing.

Which ones do you avoid?
Those with beehives—and dead trees.

Any words of wisdom for novices?
Always start with a teacher, wear a helmet, and use a harness and rope.

Who was your most impressive student?
An 85-year-old. He made it up a hundred-foot white oak.

What surprising skills have you acquired?
Once in a while someone's hair gets caught on a branch, and I have to give an emergency haircut.
—Valerie Waterhouse